Quick load pressure pot

ABSTRACT

A pressurized cylinder for receiving liquids to be sprayed from connected equipment. The cylinder includes a movable piston that facilitates quick loading and cleaning as it is adjusted to predetermined positions.

United States Patent [191 McLeod QUICK LOAD PRESSURE POT [76] Inventor: Harold D. McLeod, 11167 Ryerson,

Downey, Calif. 90240 [22] Filed: May 11, 1973 [21] Appl. No.: 359,506

Related US. Application Data [63] Continuation-impart of Ser. No. 238,595, March 27,

1972, Pat. No. 3,733,032.

[52] US. Cl. 239/373, 141/27 [51] Int. Cl B05b 9/00 [58] Field of Search 239/373; 222/394; l4l/18,

[56] References Cited UNITED STATES PATENTS Simpson 141/27 [11] 3,829,025 1451 Aug. 13, 1974 6/1966 Cook l4l/25 5/1973 McLeod 239/373 Primary ExaminerM. Henson Wood, Jr. Assistant Examiner-John J. Love Attorney, Agent, or Firm-Ronald L. Juniper [57] i 7 ABSTRACT t A pressurized cylinder for receiving liquids to be sprayed from connected equipment. The cylinder includes a movable piston that facilitates quick loading and cleaning as it is adjusted to predetermined positlons.

3 Claims, 4 Drawing Figures QUICK LOAD PRESSURE POT BACKGROUND OF THE INVENTION This is a continuation in-part of my co-pending application Ser. No. 238,595 filed Mar. 27, 1972 now US. Pat. No. 3,733,032 issued May 15, 1973.

Prior to the development of this apparatus there was not any handy, portable spray equipment which could produce quality results and be easily cleaned. Such equipment generally required disassembling for cleaning. The time and trouble required for this operation virtually precluded their use for many jobs such as, for example, two part epoxy material which solidifies very quickly.

Accordingly, it is the primary purpose of this invention to provide efficient spray equipment apparatus that is portable, easy to use and which can be cleaned quickly without disassembly.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pressure pot cylindrical receptacle and associated spray equipment in accordance with this invention. I

FIG. 2 is a partly fragmented, longitudinally sectioned view of the pressure pot and internal apparatus taken through 2-2 in FIG. 1.

FIG. 3 is a cross-sectional view of the pressure pot taken through 3-3 in FIG. 2.

FIG. 4 is a cross-sectional view of the'pressure pot taken through 44 in FIG. 2.

DESCRIPTION OF THE INVENTION Referring to the embodiment of this invention shown in the drawings the pressure pot for receiving liquid to be sprayed is a cylindrical receptacle formed with externally threaded ends onto which are screwed, respectively, an internally threaded mating top cap 22 and a bottom cap 24. A shaft 26 is slidably mounted to run through the center axis of the cylindrical receptacle 20 through a mating hole 28 centrally positioned in the top cap 22. The shaft 26 is long enough to extend through an opening 30 in the bottom cap 24 and into the bottom of the interior of an axially aligned pipe-like loading valve 32 extending down from the bottom cap 24. A loading inlet 33 opens from the bottom of the loading valve 32.

On the bottom of the shaft 26 a leather cup 34 is secured by screw 36. This cup 34 is of a sufficient size to fill and substantially seat the interior of the loading valve 32 surrounding shaft 26 when it is pushed down into the valve 32 until it also closes loading inlet 33. As the shaft 26 is raised, liquid entry is possible through the inlet opening 33 and valve 32 into the interior of receptacle 20. Leakage from the receptacle 20 is pre-.

squeeze nut 35A can be screwed tighter if leakage isv detected, thereby serving as a packing.

A slidably mounted piston rides shaft 26 on a circular, central, axially aligned hole 42 extending therethrough which mates with shaft 26. The exterior of piston 40 is flattened on its top and part of the bottom surfaces and is formed as a circular disc slidably mating with the constant axially aligned shape of the interior of cylinder 26. An O-ring 44 is mounted in a groove around the exterior circular surface of piston 40 and another O-ring 48 is mounted in a circular groove cut in hole 42. These O-rings are preferably madeof polytetrafluoroethylene and are of sufficient size and placement that sealing is provided in the adjacent abutting surfaces. A squeeze nut 50 is screwed into mating threads in the top of the hole 42 in piston 40. It is positioned to press against O-ring 48 and can be adjusted to prevent leakage. In order to provide an especially effective pressure seal a ring-shaped cup 51, preferably made of polytetrafluoroethylene, is secured flat against the bottom of piston 40 with its downturned circumferential lip 51A slidably bearing against the interior wall of cylinder 20.

Cut into the bottom surface of piston 40 within hole 42 and adjacent to the engaged shaft 26 is a slotted keyway 52. A key 54 isformed as a small rod extending through a lower portion shaft 26. The key 54 is of such,

' a size and shape, that it can fit into the keyway 52 when the shaft 26 is raised to the point of mating of these respective parts. When so mated the keyway 52 provides an internal slotted portion within which key 54 can be engaged by turning the shaft 26 about one-half turn. Thus, the piston 40 is locked on the shaft 26 and will be raised and lowered together. The piston 40 can be unlocked from the shaft 26 by turning the shaft 26 about one-half turn in the reverse direction from that through which it was locked until the key 54 is positioned over an open area through keyway 52 and thereby disengaged from the interior slotted portion therein. A round knob 56 secured by a pin 57 is mounted on the top end of shaft 26 to facilitate handling. The key 54 is located on shaft 26 so as to allow pulling piston 40 to the upper interior of cylindrical receptacle 20 when raised and to permit the bottom of shaft 26 to reach the inlet 33 in valve 32 when lowered.

On the top surface of cap 22 a closable hole of air valve 60 communicates therethrough into the interior of receptacle 20. Cut through the side of receptacle 20 is an air pressure inlet 62 (connected to a screwmounted inlet coupling 63) which communicates with the interior of receptacle 20 and is positioned so that it is lower than piston 40 when piston 40 is in the upper position as shown in FIG. 2. A fluid outlet passageway 64 is formed in bottom cap 24 located to communicate with the interior of receptacle 20 and a screw mounted outlet coupling 66.

The inlet coupling 63 is connected to a pressure regulator valve 68 onto which a bleed-off pressure relief valve 70 and a pop-off safety valve 72 are attached. A

' coupling provides an interconnection'between the closed. A handle 92 with a hook 94 on the end extends out from the bottom end of cylinder 20.

Protruding from the top of piston 40, positioned and sized to mate with the hole for air valve 60 when piston 40 is in its upper position, is a valve plug formed with leather cup 100 bottom portion upon which are axially mounted a pair of spaced disc shaped grommets 102 and 104. In order to lock piston 40 in its upper position, a slide plate 106 held by a swivelly mounted ring slide keeper 108 is positioned to swing into and engage in the locking recess space between grommets 102 and 104. A spring 110 normally pulls the plate 106 into a disengaged unlocked position.

In use spray apparatus such as shown in FIG. 1 is attached to the receptacle 20. The air valve 60 is opened and the shaft 26 is pulled up and turned to lock it to piston 40. Then the connected shaft 26 and piston 40 are pushed down to the bottom of the receptacle 20. A bucket of the fluid material to be sprayed is provided and the end of the loading valve 32 is dipped into it. When the shaft 26 is pulled up material from the bucket is sucked through inlet 33 into receptacle 20. The shaft 26 is raised until the attached piston 40 is in the upper portion of receptacle above inlet 62 as shown in FIG. 2. The receptacle 20 is now loaded with material to be sprayed. Air valve 60 is closed so as to lock piston 40 in its upper position by vacuum pressure within this sealed portion of the system. The shaft 26 is turned so as to mechanically release piston 40 from the engagement formed between key 54 and key-way 52. Then, the freed shaft 26 is pushed all the way to the bottom of the loading valve 32 so that the cup 34 provides a seal at the fluid inlet 33. Though ordinarily, the leather .cup 100 of the valve plug will be secured in the hole of valve 60, it may be necessary on occasion, to mechanically lock the piston 40 in its upper position by pressing plate 106 until it securely engages locking recess between grommets 102 and 104.

The particular preselected pressure for the material to be sprayed is set on the air pressure regulator 68. Then spraying in a conventional manner is done with the spray gun 88, which when trigger actuated, causes pressure through inlet 62 to force material from receptacle 20 through outlet hose 90 to the spray gun 88. When the spraying is completed the air compressor (not shown) is turned off and receptacle 20 is bled of air under compression by opening pressure relief valve 70.

ln order to clean the equipment, the air valve 60 is opened and shaft 26 is pulled up and turned to engage with piston 46. Then the end of the loading valve 32 is dipped into a bucket of cleaning solvent and the shaft '26 is raised up and down (thereby correspondingly moving the engaged piston 40 within receptacle 20) until receptacle 20 is cleaned. To clean the outlet hose 90 and other connected equipment load the receptacle 20 with cleaning fluid in the same manner as described previously for spraying material, turn compressor on and spray by trigger release of the spray gun 88 as when spraying material. This quickly cleans the apparatus and allows the use of two part materials which set up quickly, such as epoxies, that would otherwise tend to set up before conventional cleaning could be completed.

The form of this invention shown and described hereinbefore is not meant as limitation on the structures and apparatus which may be used so long as encompassed by the scope of the claims herein. Rather, this specification is intended as illustrative of one embodiment which incorporates structure and apparatus disclosing the concept of this invention. Other forms and modifications within the spirit of this invention are intended to be covered by the defined claims.

What I claim as my invention is:

1. A pressure pot for material spraying equipment including: a cylindrical receptacle capable of being sealingly closed, said receptacle having a material inlet, an air pressure inlet and a material outlet; a piston slidably mounted within said cylindrical receptacle and sealingly conforming to the interior thereof; means for moving said piston between a material loading position wherein said material inlet is open, and a loaded position wherein said piston permits communication between said air pressure inlet and said material outlet within said receptacle, and wherein movement of said piston from said loading position to said loaded posi tion can create suction induced loading of material into said receptacle through said loading inlet; means for holding said piston securely as it is moved from said loading position to said loaded position; means for locking said piston in said loaded position; means for closing said material inlet; and an axial shaft movably mounted within said receptacle and protruding through a mating top central opening therethrough, said piston having a central opening, mating within which said shaft is slidably mounted, an O-ring with an abutting adjustable squeeze nut sealingly encircling said shaft in said top central opening of said receptacle and an O- ring with an abutting adjustable squeeze nut sealingly encircling said shaft in said central opening.

2. A pressure pot as defined in claim 1 wherein there are means for holding said piston in its upper position including a valve opening through the top of said cylindrical receptacle and a valve plug protruding from the top of said piston, wherein said valve plug is aligned to mate with said valve opening and be held therein sufficiently tight to prevent said piston from dropping under the pressure of normal use; means for locking said piston in its upper position within said cylindrical receptacle; wherein said valve plug includes an upper portion which protrudes above the top of said cylindrical receptacle when mated in the valve opening therethrough, said upper portion being formed with a lock receiving means and a manually actuated lock on said cylinder top capable of engaging said lock receiving means thereby holding said valve plug locked in position.

3. A pressure pot as defined in claim 2 wherein said lock receiving means is a recess in the side of said valve plug and said lock is a swivelly mounted slide plate adapted to engage securely in said recess. 

1. A pressure pot for material spraying equipment including: a cylindrical receptacle capable of being sealingly closed, said receptacle having a material inlet, an air pressure inlet and a material outlet; a piston slidably mounted within said cylindrical receptacle and sealingly conforming to the interior thereof; means for moving said piston between a material loading position wherein said material inlet is open, and a loaded position wherein said piston permits communication between said air pressure inlet and said material outlet within said receptacle, and wherein movement of said piston from said loading position to said loaded position can create suction induced loading of material into said receptacle through said loading inlet; means for holding said piston securely as it is moved from said loading position to said loaded position; means for locking said piston in said loaded position; means for closing said material inlet; and an axial shaft movably mounted within said receptacle and protruding through a mating top central opening therethrough, said piston having a central opening, mating within which said shaft is slidably mounted, an O-ring with an abutting adjustable squeeze nut sealingly encircling said shaft in said top central opening of said receptacle and an O-ring with an abutting adjustable squeeze nut sealingly encircling said shaft in said central opening.
 2. A pressure pot as defined in claim 1 wherein there are means for holding said piston in its upper position including a valve opening through the top of said cylindrical receptacle and a valve plug protruding from the top of said piston, wherein said valve plug is aligned to mate with said valve opening and be held therein sufficiently tight to prevent said piston from dropping under the pressure of normal use; means for locking said piston in its upper position within said cylindrical receptacle; wherein said valve plug includes an upper portion which protrudes above the top of said cylindrical receptacle when mated in the valve opening therethrough, said upper portion being formed with a lock receiving means and a manually actuated lock on said cylinder top capable of engaging said lock receiving means thereby holding said valve plug locked in position.
 3. A pressure pot as defined in claim 2 wherein said lock receiving means is a recess in the side of said valve plug and said lock is a swivelly mounted slide plate adapted to engage securely in said recess. 